feat(aggregation-mode): add datasources and improve grafana dashboard

[maximopalopoli]

Description

Description of the pull request changes and motivation.

How to test

1. Start Ethereum Package:

make ethereum_package_start

2. Start gateway and payments poller:

make agg_mode_gateway_start_local
make agg_mode_payments_poller_start_local

3. Start the metrics module with:

make metrics_start

Now you can see the Aggregation Mode dashboard on http://localhost:3000/dashboards.

Type of change

Please delete options that are not relevant.

• New feature
• Bug fix
• Optimization
• Refactor

Checklist

• “Hotfix” to testnet, everything else to staging
• Linked to Github Issue
• This change depends on code or research by an external entity
  • Acknowledgements were updated to give credit
• Unit tests added
• This change requires new documentation.
  • Documentation has been added/updated.
• This change is an Optimization
  • Benchmarks added/run
• Has a known issue
  • Link to the open issue addressing it
• If your PR changes the Operator compatibility (Ex: Upgrade prover versions)
  • This PR adds compatibility for operator for both versions and do not change crates/docs/examples
  • This PR updates batcher and docs/examples to the newer version. This requires the operator are already updated to be compatible